An Ugi reaction, commonly referred to as a four-component condensation (4CC), involves the reaction of a ketone or aldehyde, an isocyanide, a carboxylic acid and an amine. The reaction, which yields a bisamide, is depicted as follows: ##STR1##
This reaction is of particular interest in peptide synthesis where an N-protected amino acid or peptide and/or an isonitrile containing a C-protected carboxyl group would be employed.